Glanza Rear Brakes Sticking On

Pops_20

Hi all, having some problems with the brakes on my car, wondering if anyone knows of a quick fix.

My car (1999 starlet glanza) was left sitting for a 8 days with the handbrake applied. When I drove it off for the first time I noticed that the brakes had stuck on and I had to give it a bit of welly to get the car going, but they released easy enough. This has happened before with this car so I wasn't surprised.

However today I've noticed that the rear brakes seem to be sticking on while driving. The car needs more throttle to get going, the car barely rolls on a hill with the foot off the brake and some light scoring has appeared on the outside edge of both rear disks.

I know this is a common problem with these cars, does anyone know of a way to stop this? Thanks

CJhaughey

Remove caliper mounting bolts, inspect and clean/regrease the slider pins with correct grease.
Remove pads inspect and clean piston underneath rubber boot.
Clean corrosion off brake carrier and refit pads.

Pops_20

Would this be an easy enough job you reckon?

I'd be handy enough with DIY but have never gone near brakes. Are there any special tools required other than a socket set and a wire brush? Thanks

CJhaughey

Its easy but you need to be aware of what you are doing, Have you any silicone grease for the slider pins, or rubber grease? You will need that to lubricate the sliders after cleaning.

Pops_20

I don't have any of that. Can you use copper grease or the special high melting point stuff for brakes?

I'm aware of how the calliper is bolted together and what the slider pins do etc but don't want to get stuck half way through the job.

Can the carriers be clean with just a stiff wire brush? Also I presume the pistons won't be moved and need to be wound back or anything??

CJhaughey

Pops_20 wrote: »

I don't have any of that. Can you use copper grease or the special high melting point stuff for brakes?

I'm aware of how the calliper is bolted together and what the slider pins do etc but don't want to get stuck half way through the job.

Can the carriers be clean with just a stiff wire brush? Also I presume the pistons won't be moved and need to be wound back or anything??

Copper grease is not suitable for contact with rubber such as slider pins or piston boots. It will swell and degrade rubber.
If you can wait until you get the proper grease then do the job, Stripping and cleaning them will work short term but they really need lubrication to keep working.
Try cleaning rust off the caliper carriers it can't hurt and a little copper grease where the pads sit into the carrier would be no harm.

Pops_20

Is there special grease you can buy for working on brakes? Can this also be used to lubricate the back of the pads and where they contact the carrier?

shietpilot

Pops_20 wrote: »

Is there special grease you can buy for working on brakes? Can this also be used to lubricate the back of the pads and where they contact the carrier?

Use copper grease for the back of the pads where they contact the carrier.
Use silicone grease for the sliding pins which are in contact with rubber.

Pops_20

Thanks for all the suggestions. I took apart the calliper today and tried to fix the problem.

Cleaned the calliper and carrier of brake dust, lubricted the back of pads and the mounting lugs. Also checked the slider pins which were already well lubricated and cleaned up the face of the piston.

After all this and putting it back together, the pads are still clamping down lightly on the disc. As a result, the disc and wheel are getting really hot and the car is slow to accelerate.

Any ideas what could be causing this? The only thing I can think of is that the piston would be stuck in one position, but it does move out when the pedal is pushed, so that rules that out.

CJhaughey

Did you pull the rubber dust boot off the piston and pump it out and clean the piston?
Its quite likely that the piston could be corroded under the boot and outside the seal which can stop it retracting.
Don't pump it all the way out just far enough so you can see the area that is usually covered up.
clean and grease it and refit.
Also check how far the pads are worn, have they much meat left on them?

Pops_20

I didn't take the boot off the piston, but thanks I will try that.

So you are saying,
- Pull the rubber boot off the piston
- Pump the pedal a few times to get the piston out a bit
- Clean up any corrosion on the piston with a blade/wire brush/ brake cleaner??
- Put the rubber boot back
- Wind back piston and reassemble everything?

Is it easy to get the boot off and on without damaging it?

The pads have a good bit left on them, about 5mm I reckon. Thanks for the help

CJhaughey

Pops_20 wrote: »

I didn't take the boot off the piston, but thanks I will try that.

So you are saying,
- Pull the rubber boot off the piston
- Pump the pedal a few times to get the piston out a bit
- Clean up any corrosion on the piston with a blade/wire brush/ brake cleaner??
- Put the rubber boot back
- Wind back piston and reassemble everything?

Is it easy to get the boot off and on without damaging it?

The pads have a good bit left on them, about 5mm I reckon. Thanks for the help

Yes but be careful with the blade on the piston, you don't really want to scratch it as they can leak.
If you really want to do a good job and aren't too phased by it, remove the whole piston from the caliper.
carefully pick the square O-ring out of the groove and clean under it, they sometimes rust under the seal and it tightens on the piston.
Fine wet and dry works well on the piston and a decent sharp pick to clean the seal groove.
But see if cleaning the piston works first before you go down that road.